What Are Carbohydrates and Why Do We Need them?

The dreaded word CARB has been focused on as a bad word in the fitness industry for a long time now. And now it's also a bad word for the mainstream public, thanks to things like the Atkins Diet, which classifies carbs as EVIL. The general public now has preconceived notions that all carbs must be eliminated in order to lose weight, and look and feel fit.

While this is somewhat true, it's really not a FACT! Bodybuilders do sometimes cut carbs, but they do it because, as their diets are already low fat diet, and protein can't be decreased in order to keep muscle. Carbs are the only variable that can be manipulated for fat loss. Following a low carb diet happens just by default, and not because all carbs are bad and evil and make you fat!

This is the typical image of carbs. Pasta and breads are really not the best choices!

Some people need a very small amount carbs to function, and some need more. Everyone's body is very different, but we all NEED some kinds of carbs or our bodies WILL MAKE THEM from other sources, such as the breakdown of proteins.

Not to get too in-depth and confusing, but carbs are a sort of precursor to ATP, which is the main energy molecule our bodies use to function. It's an easy step top make ATP from a carb, but if the body is lacking carbs, guess what - our bodies will take a few more steps and make a protein into a carb and then into ATP! So even if you don't eat any carbs, you still have carbs in your body!

One of my favorite carb drink powders is Waxy Maize.  It's fast-acting and slow release.

Here is a quick look at carb metabolism taken from : healthypinoy.com

Carbohydrate metabolism in the mouth
The metabolism of carbohydrates begins in our mouth. The first step is mastication -- chewing. When we chew, food is mechanically divided into smaller pieces and is mixed with an enzyme in our saliva (salivary amylase) that chemically breaks down carbohydrates into its simpler components.

A carbohydrate may be compared to a chain with many links. Each link is a monosaccharide (literally one carbohydrate or one sugar). A series of links forming a chain is a polysaccharide (several carbohydrate or sugar).

Chewing mechanically cuts the chains (polysaccharides) into more manageable chunks while salivary amylase cleaves one link from the divided chunks, releasing a monosaccharide.

Carbohydrate metabolism in the stomach
Once we swallow our food, it passes through our chest via the esophagus into the stomach. In the stomach, the mechanical breakdown of carbohydrates continues. It takes about four hours before a meal we eat completely passes out of the stomach. During that time, food is ground by repetitive and forceful contraction of the stomach and transformed into a semi-liquid substance called chyme.

Chyme, to continue our analogy, is made up of very short chunks of chain composed of one to five links each. The very short chunks facilitate the further chemical breakdown of carbohydrates in the small intestine.

Carbohydrate metabolism in the intestines
Chyme is slowly released from the stomach into the small intestines. Here the chemical breakdown of carbohydrates, which started in the mouth, is completed. Enzymes from the pancreas flow into the small intestine together with chyme. The enzyme break the very small chunks of carbohydrate into individual links. The long chain of carbohydrate which was mechanically broken down into smaller chunks in the mouth and stomach are now broken down into separate links (monosaccharides). Monosaccharides, of which glucose is well known, are taken up by the cells of the intestines and go into the bloodstream.

Carbohydrate metabolism in the blood
Once in the blood, glucose (and other monosaccharides) is used by the cells of the body as a source of energy. A molecule of glucose may be taken up by the cell, broken down further into its components and, by a series of chemical reactions, transformed into ATP (adenosine triphosphate), the primary energy currency of cells.

The formation of ATP marks the end of the catabolic metabolism (breakdown) of carbohydrates. Cells of the pancreas, liver, and fats use glucose in unique ways.

Carbohydrate metabolism in the pancreas
After a meal, the glucose level in the blood goes up. This high level of glucose causes the pancreas to release insulin, a hormone that affects the metabolism of glucose in the liver and fat tissues.

Carbohydrate metabolism in the liver
Insulin promotes the uptake of glucose by liver cells. In addition to using glucose as a source of energy, liver cells store the excess glucose as glycogen. Glycogen is converted back to glucose when the sugar level goes down between meals.

Carbohydrate metabolism in fat cells
Fat cells take up glucose from the blood and convert it to ATP. When there is an excess of ATP, as when caloric intake exceeds caloric requirement, fat cells convert ATP to fat. This is the reason why any excess in our caloric intake, be it protein, carbohydrates or fat, increases our body fat and, consequently, our body weight.

Our understanding of how the body uses carbohydrates highlights our need to eat a balanced diet to meet our daily caloric requirement.

I hope this doesn't confuse anyone and sheds some new light on the feared carbohydrate monster people think is lurking in foods.